This application is related to commonly owned U.S. Design Patent Application Ser. No. 29/126,444 filed concurrently herewith entitled xe2x80x9cDesign For: DOMED CUP LIDxe2x80x9d, the entire content of which is expressly incorporated hereinto by reference.
The present invention relates generally to lids for beverage drinking cups. In especially preferred forms, the invention is embodied in a domed cup lid which is especially useful for cups containing frozen carbonated beverages.
Many popular beverages are dispensed with carbonation. The carbonation will thus tend to make the beverage foam somewhat creating a xe2x80x9cheadxe2x80x9d which can spill over the sides of the cup in which it is dispensed and contained. This xe2x80x9cheadxe2x80x9d can be particularly acute for frozen carbonated beveragesxe2x80x94that is, beverages which contain flavored ice particles which are highly viscous, but nonetheless capable of being drawn through a straw. In particular, the head on frozen carbonated beverages is fairly cohesive and relatively self-supporting. As a result, a pleasing visual appearance of the beverage in the cup can be obtained since the beverage can literally be dispensed over the height of the cup lip thereby creating a mounded overfill.
Hemispherical lids are known which allow such a mounded overfill to be achieved, but yet prevent it from spilling over the sides of the cup, as shown in U.S. Pat. No. 4,508,235 (the entire content of which is expressly incorporated hereinto by reference). Specifically, the cup lid depicted in this prior-issued ""235 patent is hemispherically shaped and defines a circular opening at the top of the lid to permit the dispenser tap to be inserted therethrough and thereby allow the beverage to be dispensed into the cup with the hemispherical lid in place.
Several problems can ensue, however, when such conventional cup lids are employed for frozen carbonated beverages. For example, the dispenser tap can form a seal against the edge of the lid opening which will cause a pressure force to build inside the cup lid and thereby potentially forcing the lid to separate from the cup. Furthermore, such conventional lids can promote overfilling of the cup since there is a tendency to dispense the beverage until it reaches the lid opening. As a result, little or no room is left to allow expansion of the frozen carbonated beverage resulting is spillage over the sides of the lid and cup.
More recently, a domed cup lid having an apical reentrant well and an angulated opening formed at the terminal surface of such reentrant well has been proposed in commonly owned U.S. patent application Ser. No. 09/410,070 filed on Oct. 1, 1999 (the entire content of which is incorporated hereinto expressly by reference). The angulated opening disclosed therein serves to define vent spaces between the edges of the opening and the dispenser tap to preclude pressure build-up when beverages, especially carbonated beverages, are dispensed. Moreover, the terminal surface of the recessed reentrant well portion in the lid of the ""070 application provides a visual fill line to prevent overfilling of the beverage while also defining a convenient head space thereabove to allow for beverage expansion and thereby minimize (if not prevent entirely) spillage. The reentrant well also provides a reservoir to retain excess beverage which might be forced outwardly from the opening.
While the lid of the ""070 application represents a significant advance in this art and an improvement over conventional domed lids, continual improvement is sought. It is towards providing such improvement that the present invention is directed.
Broadly, the present invention is embodied in a domed lid for a beverage cup comprised of an arcuately convex lower side wall section, and an arcuately convex upper side wall section protruding upwardly from the lower side wall section. Most preferably, each of these upper and lower side wall section is in the form of a respective spherical surface, with the upper side wall section having a lesser radius of curvature as compared to the radius of curvature of the lower side wall section.
In particularly preferred forms of the invention, cup lids are provided having an arcuately convex lower side wall section establishing a circular base skirt adapted to being attached to an upper lip of a cup; and an arcuately convex upper side wall section. The upper side wall section is joined at a lower edge region thereof to the lower side wall section by means of an annular concavity, and protrudes coaxially upwardly from the lower side wall section to an annular apical edge region. The upper side wall section includes a reentrant well recessed below the apical edge region and defines an opening in a terminal surface thereof.
These aspects and advantages of the present invention will be further understood by reference to the following detailed description of a preferred exemplary embodiment thereof.